Damping device for grade-indicators.



" an sind 1:1 iai-iniciar Joiinr K. STEWART, or CHICAGO, iLLir-iois,Assis-non ToVsTnwanT-Wennnn ernan- OMETEB, CORPORATION, or cHicAeo,rLLIrioIs, A consonancia or vineinia,

DAMING DEVCE FOR GADE-INDICATORS.

Specification Of Letters laatent.

Application filed January 27, 1913. Scrialvlo. 744,343.

To all whom it may concern Be it known that I, JOHN K. STEWART, 'a

citizen of the United States, residing at Chicago, in the county of Cookand Stateof 5 Illinois, have invented new and/useful lmprovements .inDamping Devices for Grade- Indicators, 'of which .the following is aspecification, reference vbeing had to the accompanyingA drawings,forming a part o thereof. u

The purpose ofthis invention is to provide means for damping the swingof the pendulum and its connected indicating means in a grade meter torender the instru- 5 ment dead-beat, and is particularly adapted forembodiment in such instrument `whencombined.with a speedometer or anodometer for use on vehicles.

It consists of the features and elements shown and described in thedrawings as indicated in the claims.

In the drawings :-Figure l is a front elevation of a combinedspeedometer, odometer and grade indicator with parts broken awayomitting, however, the odometer train indicated therein. Fig. 3 is aplan view of the magnet of the speedometer with the-position of thearmature button of the damping device indicated in dotted lines. Fig, 1iis a det-ail elevation partly in section showing the modifiedconstruction ,for a grade meter dampingl device. Fig. 5 is a detailyview taken similarly to Fig. .4 and showing another modiied form of agrade meter ,damp ing device.

As shown in the drawings, this deviceis embodied in a combinationinstrument for motor vehicles, which includes a magnetic speedometer offamiliar type which comprises a magnet, A, rotatably mounted upon ashaft, B, for influencing a ,drag disk, C, whose downwardly hangingiiange, C1,

'carries the speed indicating scale, C2, which appears before thewindow, C, in the casing,

D. The grade indicator which is mounted in the same casing, D, comprisesa pendulum, E, carrying rigidly a' segmental gear, E1, which meshes witha pinion, E2, xed to an indicating wheel, E3, carrying a gradeindicating scale, E4, positionedto appear at a window, E5. in thecasing, D. It is obvious that the p sitionV of the. wheel, E3, with toreveal the internal construction. Fig. 2

respect to any xed point, as, E, on the casing will indicate theinclination of the vehicle on whichvthe-instrument :is mounted Patented@et it?, itit. v

if the scale, E4', is correctlyproportioned for thepuipose, it is found,however, that sudden accelerationv of the vehicle-in starting orstopping quickly will overcome the in# ertia of the pendulum, E, andwiilthus move the scale of the grade indicator even oiilevel ground, andthat if. a' damping deviceis employed which nierelytends to opposefmovement ofthe grade' indicatingparts,

these parts 'having been disturbed from their proper position' by thesudden 'acceleration of the vehicle will notreadily, return to such.

proper position because hinderedfby the damping device, and the reading.will thus be untrue. This diiiiculty is overcome byl the presentinvention which employs a brake member,y F, shown as a normallyincontact with 'the rim of theindicating wheel, E3, while its lower endrests upon afspriiig arm, F2, iixed to av frame member, D1, of theinstrument. The frame member, '.Dl, extends directly above the inagnet,A, of the Aspeedometer which is constanti-y in rotary motion when thevehicle is traveling. The forni-ofv the magnet is indicated in Fig. 3which vshows a notch, A1, whose function issi-milai.' to the more usualair gap ofy a horse-shoe or split rin mag net, such as is commonlyemploye in instruments of thisclass; that is, the .poles of the magnetwill be. found to be located at either side ofthe gap or notch, A1, anda kportion of the magnetic uii passes outside the-metallic circuit intothe air at this point vand is thus available for iiiiuencing the dragdisk, C. The magnetic veld thus created at this part of the inagnisfurther utilized for purposes of this invention by mounting loosely inthe frame'meinber, 3D1, above the path of rotation of the notch, AE, orin the --vicinity of said path, an armature button,

I pin carried looselyin albracliet, F1, and having its upper 'endv F3,whose head,1id`4, engages' the top side of the spring arm, F2, so thatevery time `the notch, A1, of the magnet passes under the armaturebutton, l `3,in itsyrotatiom the said button is drawn .ldow'nwfardly bythe magnetic force, thus ietracting' the spring arm, F?,and'relieving-the brake pin, F, of its pressure'so as to permit rotationof the indicating Wheel, E, if thev influence of 'gravityx'onlgthependulum, E, at the instantmagnet, A, in their lv,by strongly attractinglinie/J, with the spring arm,

should tend to eliect such rotation. Since the rotation of the magnet,A, is normally at a moderately rapid rate, the balie pin, F, is given arapid tapping action with respect to the indicating` wheel, E3, and`thus permits only an intermittent movement of the latter and renders itpractically deadbeat at all times. It' desired, the engagedish C, steadyat the correct position corrcspending to the .speed to be indicated, thearmature button, F, may be provided on its under side with an extendingspring arm, F5, preferably of non-magnetic material, which will be moveddownwardly with the armature when the latter is attracted by the passageof the magnet poles, so that its tip, F, vvill be drawn temporarily intocontact with the top surface oit the drag dislr, C, and will thus tendfrictionally to absorb any excess movement of said disk and Will assistin bringing it to rest at the proper indicated position.

The modification of the damping device 1to1' the grade meter isillustrated in F ig. 5 as comprising merely a tiXedl Y mounted soft ironpost, G, having` its loiver end 'within the range of influence of thepoles of the rotation, and its upper end extending toward the rim of thegradeu indicating wheel, E3. The rim of said Wheel is formed with ayseries ot projecting teeth, E, preferably correspondingr each to a scaledivision of the graduated tace of the Wheel; and the upper end of thepost, Gr, is reduced or tapered to a cross-section substantially equaltothat ot' one of said teeth, E8. Thus, as the poles ot the magnet, A,pass under the. lower end ot the soft iron post, G, said post will hetemporarily magnetized, and the concentrated magnetic flux at its uppertapered end will tend for the instant to hold the indicating,` wheel,E3, stationary the nearest oi' its teeth, lhis actiony icingintermittent u'ill not hinder the Wheel, E, from assumine the correctgrade-imlicating position to vvhirli the penduluni, E, tends to .moveit, but .'vill eliectively check other movement due to the suddenacceleration of the vehicle. lit', on the other hand, it is preferrednot to depend at all upon the magnetic principle tor operating thedampingr device, the nmdiiication illustrated iii i may be employed, inwhich a cam shoulder, $5.2, on 'the under side et' the magnet, A, isarranged to ae'tuate a lever, H, connected through av F2, for With-Leccese drawinfr the latter and tem norarilv releasb ing the brake pin,F, during the lrotation ot' and means carried thereby adapted for rendering;` said brake device alternately operative and inoperative withrespect to said pendulum.

Q. In a grade meter comprising a pendulum, braking means for saidpendulum including a brake device` ar rotating member, means foryieldingly holding said brake device in operative position with respectto the pendulum, and means operatively con nected to said rotatingmember and adapted for intermittently reti-acting said brake device.

3. In a grade meter comprising a. pendulum, in combination with acontinuously rotated shaft, brakingY means :tor said pendulum includinga brake. device, and means operatively connected with the shaft adaptedfor rendering said brake device alter nately operative and inoperativewith respect to said pendulum.

et. In combination with a magnet mounted for rotation of its poles aboutan axis, a grade meter comprisingq a, pendulum, and braking means forsaid pendulum including a brake device comprising an armature positionedproximate to the path of rotation of said magnet poles whereby therotation of said magnet serves to render said brake device alternatelyoperative and inoperative with respect to the pendulum.

In combination with. a magnet mounted for rotation of its poles about anaxis, a grade meter comprising a pendulum, and braking` means for saidpendulum including a brake device comprising a brake and a springmounted 'for yieldingly retaining the brake in operative position withrespect to the pendulum, and an armature positioned proximate to thepath of rotation of the said magnet poles and connected With the saidspring whereby the rotation of the magnet serves to attract saidarmature for releasing the brake from the spring pressure. y

(i. in. a grade meter comprising* a pendulum, and a Wheel geared uptherefrom, brain ing means for said pendulum including a brake devicecomprising a hrakeymember mounted for Contact with said wheel, a

spring positioned to maintain such contact,

a rotating member, and means 'operatively oonnectedthereto adapted forintermittently withdrawing said spring toirelease the wheel from thebrake.

7,-In a grade meter comprising a pendulum, and a Wheel geared uptherefrom braking means for said pendulum inclu ing a brake devicecomprising a pin mounted for contact with said wheel, the contactingpor-` tion of said wheel being knurled -or roughened, a springpositionedto maintain such contact, a rotating member, and means operativelyconnected thereto adapted for intermittently withdrawing said spring torelease the wheel from the rake.

8. In combination in a magnetic speedometer, comprising a rotatingmember having a magnet mounted for rotation of its poles about an axisand a drag disk mounted proximate to the path of rotation of said poles,a grade indicator comprising a pendulum-operated member, a brake device,means for yieldingly holding said brake device in operative positionwith respect to the pendulum-operated member, means operativelx7associated with the said rotating member and adapted for independentlyretracting said holding meansand a brake device for the drag diskoperatively connected with said retracting means and positioned forcontact with said drag disk during the retraction of the pendulum'brake.

In testimony whereof I have hereunto set my hand-at Chicago, lllinois,this 3l day of October, 1912.

Y JOHN K. STEWART. Witnesses: v

vC. I). SMITH,

SrANHoPn HUDSON.

